Signalling device for indicating improper position of a skier

ABSTRACT

A signalling device for indicating improper position of a skier or the like comprising means attachable to the body of the skier and including means responsive to the position of the skier operatively connected with indicating means for causing a signal to indicate when the skier is not in the proper position.

United States Patent Mathaus'er Feb. 22, 1972 [54] SIGNALLING DEVICE FOR [56? Cited INDICATING IMPROPER POSITION OF "Mm fififi-E TAfgs pmgm A SKIER 2,064,603 12/ 1936 Harrison ..35/29 R [72] Inventor: William R. Mathauser, PO. Box 5, Sun 3,362,023 1/1968 McMahon ..340/279 Valley, Idaho 83353 Em J hnw Cald Primary minero we [22] filed: 1970 Assistant Examiner-Glen R. Swann, ll] [21] Appl. No.: 99,632 Attorney-Shoemaker8zMattare [57 ABSTRACT [52] US. CL ..340/279,35/29 R,200/DIG.2 [51] Int. Cl 21/00, A63b 69/18 A slgnaumg devlce f mdcatmg Improper Posmon of a Skler 581- Field of Search ..34o/279; 35/29 D, 29 A, 29 R; like mPrisin8 means attachable the of 272/57 B; ZOO/DIG. 2

skier and including means responsive to the position of the skier operatively connected with indicating means for causing a signal to indicate when the skier is not in the proper position.

32 Claims, 9 Drawing Figures L.FIG.I.

Patented Feb. 22, 1972 3,644,919

3 Sheets-Sheet 1 INVENTOR W. R. MATHAUSER ATTORNEYS Pate :nted Feb. 22, 1972 3 Sheets-Sheet z INVENTOR R E S U A H T A M R W Patentd Feb. 22, 1972 3 Sheets-Sheet, 5

FIG. 7.

FIG. 8

INVENTOR W. R. MATHAUSER ATTORNEYS SIGNALLING DEVICE FOR INDICATING IMPROPER POSITION OF A SKIER BACKGROUND OF THE INVENTION As in many sports, the most common fault in skiing is improper position, and one of the most common or basic faults in skiing is improper position or bending of the knees. Oncethe skier learns to position or bend his knees properly, the skier will progress very rapidly in acquiring more advanced skiing skills and more complicated maneuvers will be quickly accomplished by the skier. Proper positioning of the knees is one of the most difficult things for a beginning skier and even for advanced skiers to continually keep in mind, and this is extremely important since there is no time during actual movement on skis when the knees should become straight or the pressure released from the ankle and the front of the skis where it should be at all times for proper control of the skis. Unless the skier assumes proper position and thereby transfers his weight to the front of the skis so that the ski edges can sufficiently grip the snow to enable the skier to control his movements, the skier will never be able to master any of the more complicated maneuvers in skiing; and, in fact, he will never be able to really properly execute any of the movements of skiing. Once the proper position of the knees is accomplished, proper distribution of weight on the skis will follow and most of the other skiing maneuvers will then be readily accomplished.

The present invention relates generally to a means to forcibly bring to the attention of the skier that the proper exertion is not being placed on the boot for the proper distribution of weight on the skis and the attendant control of the skis accomplished thereby.

More particularly, the present invention comprises a signalling device for indicating when the skier is not in the proper position and includes a very compact and lightweight self-contained unit mountable upon the skiers body and has means for transmitting a signal to the skier when he is not in the proper position. Basically, the invention includes a battery powered unit having means mounted in the boots of the skier or adjacent the knee of the skier in a position to sense when the skiers knees are in a particular position and arranged to transmit a signal to either an audio unit, a visual unit or a vibrator or touch-sensing device to indicate when the skiers knees are not in proper position. All of the signalling devices-the audio, the visual and the touch units-are intended to accomplish the same thing; namely, notify the skier when he is not in the correct position. One or all of the units can be used independently or simultaneously and can be controlled as individual units. The purpose of providing more than one signalling unit is to avoid the human characteristic of becoming immune to certain sounds or signals and ignoring that signal. By having more than one signalling unit, when the skier becomes immune or tends to ignore one of the signalling units, another signalling device can be selected or activated, and the skier subjected to a different-type signal.

The signalling device is made in three basic parts which can be offered as replaceable components without having to purchase or replace the entire device.

To the best of applicants knowledge, the prior art does not disclose any signalling means for indicating when a skier is not in the proper position. Various attempts have been made in the prior art to enhance the control exerted by the skis by modifying the ski construction itself, but these methods and apparatus do not help the skier overcome improper position nor do they let him know when he is not in the proper position so that he may correct his form in order to become a better skier. The present invention thus provides a unique and novel device which fulfills a long felt need in the art; namely, to indieate to a skier when he is not in the proper position and to thereby greatly increase the speed with which a skier can become an accomplished skier.

OBJECTS OF THE INVENTION It is an object of this invention to provide a means for indicating to a skier when he is not in the proper position for skimg.

A further object is to provide a signalling device for sensing the position of a skier and indicating or signalling to the skier when he is not in the proper position for skiing.

Another object is to provide a signalling device adapted to be worn by a skier and including means for sensing the position of the skier and giving an audible signal when the skier is not in the proper position for skiing.

Still another object is to provide a means adapted to be worn by a skier and including means for indicating through touch when the skier is not in the proper position for skiing.

An even further object is to provide means adapted to be worn by a skier and including means selectively operable for indicating to the skier by a plurality of selectively operable signalling means when the skier is not in the proper position for skiing.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 depicts a skier wearing the present invention and with his knees properly flexed or bent for exerting the proper weight on the front of the skis where it must be for proper control of the skis.

FIG. 2 is a schematic perspective view of one form of the present invention illustrating the power source and the pressure-sensitive switch means for energizing the signalling means.

FIG. 3 is a side view in section taken along the line 33 of FIG. 2 of one of the pressure-sensitive switch means.

FIG. 4 is an enlarged partial view in section of the switch means shown in FIG. 3 illustrating greater detail of the switch means.

FIG. 5 is a perspective view of a second form of switch means.

FIG. 6 is a side view in section of the modification shown in FIG. 5.

FIG. 7 is a schematic view of a skier wearing two forms of switch means according to the present invention.

FIG. 8 is an enlarged view of a third form of switch means to be worn at the knee of the skier.

FIG. 9 is a perspective view of the ,third form of switch means according to the invention.

DETAILED DESCRIPTION OF THE INVENTION Referring now to the drawings wherein like reference numerals refer to like parts throughout the several views, a skier S is shown in FIG. 1 with his knees properly flexed or bent for exerting weight on the front of the skis where it must be for proper control of the skis. A signalling device indicated generally at 10 is mounted on the body of the skier and includes a small rectangular audio and power unit 11 having a pair of flexible leads or wires 12 and 13 connected thereto and extending downwardly therefrom along the opposite legs of the skier. The leads l2 and 13 may be suitably positioned within the ski pants of the skier such as by taping them to the inside surface of the pants. A pair of sensing units such as pressure-sensitive switch means 14 and 15 are adapted to be mounted inside the ski boots between the upper front surface of the foot and ankle and the front of the boots, respectively, and are operatively connected to the leads l2 and 13 and thus to the audio and power unit 11. A suitable signalling means 16, such as a vibrator or means for generating a mild electrical shock or the like is connected to the power unit 11 through a retractable third flexible lead or wire 17 to indicate to the skier through his sense of touch when he is not in the proper position. Although the signalling unit 16 is shown mounted to the thigh or leg of the skier, it could equally as well be mounted to other portions of the skiers body. A suitable visual indicating means such as a light 18 or the like (indicated in phantom lines in FIG. 2) may also be provided connected to the audio and power unit 11 by means of a flexible lead or wire 19. An audible signalling means such as a speaker 20 is mounted in the audio and power unit 11 for emitting a signal such as a buzz similar to the signal given in automobiles, for example, when the ignition key is left in the ignition switch.

A clip 21 or the like is fixed to the unit 11 for attaching the unit to the belt or the like of the skier. Alternatively, the unit 11 could be worn about the neck of the skier in necklace fashion or otherwise carried on the body, as desired.

The leads 12 and 13 are connected to the power unit through a suitable connection such as a bayonet connection or jack 22 disposed in the top of the unit 11. A control knob 23 is mounted on the front of the unit 11, and when the knob is turned to the left, or in a counterclockwise direction, it increases the volume of the signal emitted from the speaker 20; and when it is turned to the right, or in a clockwise direction, it serves to establish communication between the touch signal unit 16 and the pressure-sensitive switch means 14 and 15 for causing a signal to be transmitted to the skier through touch or the like. The knob 23 also functions as an on-off switch for energizing the unit and by pushing the control knob in, the unit is switched "off" and by pulling the control knob out, the unit is switched on. A suitable switch 24 is also disposed on the front of the unit 11; and when this switch is operated, both the audio portion, including speaker 20, and the remote or touch unit 16 may be used simultaneously.

The sensing units 14 and 15 may comprise any suitable type of switch means, such as mechanical or hydraulic and the like. In a preferred embodiment, the sensing units comprise flexible, generally tongue-shaped elements adapted to be mounted on the front of the foot between the boot and the front surface of the foot of the skier. The leads l2 and 13 are suitably connected to the sensing units 14 and 15 as by means of a bayonet plug 25 or the like and a position control knob 26 is mounted on the front of each of the sensing units 14 and 15 for adjusting the amount of flexure necessary in order to activate the switches.

Referring now to FIGS. 3 and 4, details of the sensing units 14 and 15 are shown. Each flexible, tongue-shaped sensing unit is made of plastic or fabric or other suitable material and has a hollow elongate opening 27 generally in the center thereof. A flexible tube 28 is disposed within the hollow opening 27 and is filled with a suitable hydraulic fluid 29 or the like. The upper end 30 of the tube has a weakened section 31 which is readily expandable by the hydraulic fluid 29 when the tongue-shaped sensing unit is flexed as seen in FIG. 6. When the weakened section of the tube expands, it engages a microswitch 32, opening the switch and deenergizing the signalling unit. The microswitch 32 is reciprocally mounted in a small hollow extension or housing 33 adjacent the upper end of the sensing unit on the front'surface thereof. The adjusting knob 26 is connected to the microswitch 32 through a threaded shaft 34 threadably received through the housing 33 for adjusting the position of the microswitch 32 in the housing 33 relative to the tube 28 whereby the amount of flexure of the sensing unit and tube 28 necessary to actuate the microswitch 32 may be varied to accommodate persons of different size or different posture so that the unit may be adjusted to the proper position for each individual.

A modification of the invention is illustrated in FIGS. 5 and 6 and is identical in every respect with the embodiment illustrated in FIGS. 1 through 4 with the exception that the sensing unit is embodied in an anklet 35 rather than in the tongueshaped member 14 or 15. A foot strap 36 is secured to the anklet 35 for maintaining the anklet in proper position about the ankle of the skier, and the sensing unit is mounted in the front portion of the anklet 35 so that when the knees are properly bent, the tube 28 will be at least partially collapsed at its midpoint 37, as seen in FIG. 6, to cause the liquid to expand the upper end 31 of the tube to operate the microswitch.

The invention as thus far described is intended to be placed at the front of the foot between the foot and boot when the conventional lace-type boot is used. However, most of the newer ski boots are hinged; and when the person wearing the boot leans forward, there is an opening or space at the back of the boot and the microswitch or sensing unit according to the present invention could be mounted in this area. With the sensing unit and switch mounted in the back of the boot, when the skier is in the proper position, the switch would be opened and no signal would be emitted by the signalling device. However, as soon as the skier assumes an improper position or straightens his knees, the switch would be closed and the signalling unit energized.

In addition to being manufactured as a separate unit adapted to be used with conventional boots, the invention could obviously be incorporated into the boot itself and with reference to the embodiment illustrated in FIGS. 1 through 4, the tongue of the boot itself could have the sensing unit therein. Moreover, the sensing unit and switch could be positioned in other parts of the boot sensitive to the pressure exerted thereon when the knees are flexed to operate the signalling device.

In use, the signalling device would be attached to the skier such as shown in FIG. 1, for example, with clip 21 hooked over the skiers belt and sensing units 14 and 15 disposed inside the boots on the front surface of the foot. The touch signalling unit 16 would be taped or otherwise positioned adjacent a portion of the skiers body and the light 18 would be mounted in a position visible to the skier, such as on the ski cap or the like. When the skier is ready to begin a run down the ski slope, he would pull the control knob 23 out to energize the system and adjust the control knob for proper volume of the speaker 20 or to cut out the speaker and energize the touch signalling unit 16. Further, the skier could operate switch 24 so that both the speaker 20 and touch signalling unit 16 could be used simultaneously. When the skier desires to stand in an upright position or for some other reason desires 'to deenergize the signalling device, he would simply push the control knob 23 inwardly.

In addition to, or in lieu of the units 14, 15 or 35 worn in the boot or at the foot of the skier, a third form of switch means 38 is illustrated in FIGS. 7 through 9. In some of the advanced skiing positions, as for example the relatively new Jet Christie or Low-down Christie, the skier assumes a sitting position as shown in FIG. 7 with the lower portion of the skiers leg extending at nearly a right angle from the ski. In this position, there may not be enough flexure or the ankle or pressure at the front of the boot to activate switch 14, 15 or 35. Accordingly, switch unit 38 is worn at the knee of the skier where most flexure occurs. Unit 38 could obviously be used in the early or less advanced stages of skiing since the knee is also bent then for proper control of the skis. The switch unit 38 comprises an upper leg strap 39 adapted to be adjustably positioned about the-upper leg of the skier adjacent the knee and made adjustable by a strap adjustment 40. A lower leg strap 41 is similarly adjustably positioned about the lower leg of the skier adjacent his knee and is adjustable by means of a strap adjustment 42.

A brace or switch mounting bracket 43 is fixed to the upper leg strap 39 as by rivets 44 or the like and extends downwardly toward the knee, terminating at its free end at the side of the knee. A similar bracket 45 is fixedly mounted to lower leg strap 41 as by rivets 46 or the like and extends upwardly toward the knee, terminating at its free end at the side of the knee and in overlapping relationship to the free end of bracket 43. The free ends of brackets 43 and 45 are pivotally connected as by a pivot pin 47 or the like extended through the ends. A suitable microswitch 48 is mounted on bracket 43 adjacent the pivot and a flexible lead 49 extends from the switch 48 to the unit 11. A switch engaging or actuating shaft 50 is threadably or otherwise suitably adjustably positioned through a bracket 51 suitably fixed on the free end of bracket 45 adjacent the pivot. A knob 52 is on the end of shaft 50 for adjusting the position of the shaft relative to the switch 48 to compensate for different skiers or different positions at which it is desired the switch 48 be actuated. When the skiers knee is properly flexed as in FIGS. 7 and 8, the shaft 50 engages the switch 48 and holds it open so that no signal is emitted by the unit 11. If the knee is not properly flexed, the shaft 50 moves away from switch 48, permitting the switch to close and a signal is given to warn or indicate to the skier that he is not in the proper position. Any suitable switch means and actuating means therefor may be used at the knee in place of the specific means shown. The unit 38 may be used instead of the units l4, or 35 or it may be used in conjunction therewith, as desired. Further, the switch means 48 may be positioned on either side of the knee and a switch may be positioned at one or both knees, as desired.

Each of the switch means, whether worn at the ankle or at the knee, and each of the signalling means, i.e., audio, visual and touch, may be provided in an independent circuit so that improper flexure of one knee will be indicated independently of the other knee. For example, a first light of one color, such as red, could be positioned adjacent the right eye and a second light of another color, such as green, could be positioned adjacent the left eye so that one or the other of the lights would be illuminated depending upon which knee is improperly flexed. Similarly, the audio system could include two sounds of different frequencies, one frequency being given when one knee is improperly flexed and the other frequency being given when the other knee is improperly flexed. This would enable the skier to tell which knee is not properly flexed.

As this invention may be embodied in several forms without departing from the spirit or essential characteristics thereof, the present embodiment is therefore illustrative and not restrictive, since the scope of the invention is defined by the appended claims rather than by the description preceding them, and all changes that fall within the metes and bounds of the claims or that form their functional as well as conjointly cooperative equivalents, are therefore intended to be embraced by those claims.

lclaim:

l. A signalling device for indicating to a skier when not assuming a correct position of the body comprising means attachable to the lower extremities of the body and including sensing means responsive to flexure of the joints of the lower extremities, the sensing means being operatively connected to a signalling means for indicating to the skier when assuming a position other than the correct position.

2. A signalling device as in claim 1, wherein said sensing means are positioned adjacent the feet of the skier.

3. A signalling device as in claim 2, including a source of electrical energy, said sensing means and said signalling means being operatively connected therewith.

4. A signalling device as in claim 3, wherein said sensing means comprises a flexible member adapted to be mounted between the foot of the skier and a boot worn by the skier and responsive to the position of the skier to establish an electrical circuit between the source of electrical energy and the signalling means.

5. A signalling device as in claim 4, wherein said sensing means has a flexible elongate tube therein, said tube being filled with a hydraulic fluid or the like and having an expandable portion which is adapted to be expanded when the tube is flexed.

6. A signalling device as in claim 5, wherein a microswitch is mounted in said sensing means adjacent said expandable portion of said tube and is adapted to be operated by said tube when the tube expands upon being flexed, said microswitch being operatively connected to said source of electrical energy for establishing and interrupting an electrical circuit between said source of energy and said signalling means.

7. A signalling device as in claim 6, wherein said signalling means comprises a speaker for emitting an audible signal.

8. A signalling device as in claim 6, wherein said signalling means includes a vibrator adapted to be positioned adjacent the body of the skier for indicating to the skier through the sense of touch that the skier or the like is not in the proper position.

9. A signalling device as in claim 6, wherein the signalling means comprises means for causing a mild electrical shock to be transmitted to the skier when he is not in the proper position.

10. A signalling device as in claim 6, wherein said signalling means comprises a speaker for emitting an audible signal, a vibrator for signalling the skier through the sense of touch, and a light for giving a visual signal when the skier is not in the proper position.

11. A signalling device as in claim 10, wherein said source of electrical energy and said speaker are mounted in an audio and power unit, and wherein a control knob is provided on said power unit for increasing or decreasing the volume of sound by the speaker.

12. A signalling device as in claim 11, wherein said control knob is operatively connected to said source of electrical energy for selectively energizing and deenergizing said signalling device.

13. A signalling device as in claim 12, wherein said control knob includes means for selectively energizing either said speaker or said vibrator.

14. A signalling device as in claim 13, wherein a switch means is provided on said audio and power unit operatively connected to said source of energy for simultaneously energizing said speaker and said vibrator.

15. A signalling device as in claim 14, wherein said microswitch is adjustably positioned relative to said expandable tube whereby the amount of expansion of said tube necessary to actuate said microswitch may be varied to accommodate persons of different size or different stance.

16. A signalling device as in claim 15, wherein said sensing means and said signalling means are connected to said source of energy by means of flexible leads or wires.

17. A signalling device as in claim 16, wherein said flexible leads are connected to said sensing means through a bayonettype connection.

18. A signalling device as in claim 17, wherein said flexible member comprises a generally tongue-shaped member adapted to be worn between the upper front surface of the skiers foot and the boot whereby when the skiers knees are flexed or bent properly for skiing, the flexible member is distorted and the flexible tube is at least partially collapsed to cause the hydraulic fluid therein to expand the expandable portion of the tube to open the microswitch.

19. A signalling device as in claim 17, wherein said flexible member comprises an anklet adapted to be worn about and encircle the ankle of the skier whereby when the skier's knees are flexed or bent properly for skiing the flexible member is distorted and the flexible tube is at least partially collapsed to cause the hydraulic fluid therein to expand the expandable portion of the tube to open the microswitch.

20. A signalling device as in claim 19, wherein said flexible tube is positioned .in the front central portion of said anklet.

21. A signalling device as in claim 1, wherein said sensing means is positioned at the knee of the skier.

22. A signalling device as in claim 21, wherein said sensing means includes switch means operable in response to the position or degree of flexure of the skier's knee.

23. A signalling device as in claim 22, wherein said sensing means is carried by upper and lower leg strap means adapted to be adjustably positioned about the leg of the skier above and below the knee, respectively.

24. A signalling device as in claim 23, wherein said switch means comprises a microswitch carried by one of said leg strap means and microswitch-actuating means carried by the other of said leg strap means.

25. A signalling device as in claim 24, wherein said microswitch-actuating means includes a shaft adjustably positioned in a bracket.

26. A signalling device as in claim 25, wherein said microswitch and said shaft are carried on respective bracket means fixed to a respective leg strap means.

27. A signalling device as in claim 26, wherein said bracket means fixed to said leg strap means are pivotally interconnected to one another.

31. A signalling device as in claim 28, wherein the signalling means comprises means for causing a mild electrical shock to be transmitted to the skier when he is not in the proper position.

32. A signalling device as in claim 28, wherein said signalling means comprises a speaker for emitting an audible signal, a vibrator for signalling the skier through the sense of touch, and a light for giving a visual signal when the skier is not in the proper position. 

1. A signalling device for indicating to a skier when not assuming a correct position of the body comprising means attachable to the lower extremities of the body and including sensing means responsive to flexure of the joints of the lower extremities, the sensing means being operatively connected to a signalling means for indicating to the skier when assuming a position other than the correct position.
 2. A signalling device as in claim 1, wherein said sensing means are positioned adjacent the feet of the skier.
 3. A signalling devicE as in claim 2, including a source of electrical energy, said sensing means and said signalling means being operatively connected therewith.
 4. A signalling device as in claim 3, wherein said sensing means comprises a flexible member adapted to be mounted between the foot of the skier and a boot worn by the skier and responsive to the position of the skier to establish an electrical circuit between the source of electrical energy and the signalling means.
 5. A signalling device as in claim 4, wherein said sensing means has a flexible elongate tube therein, said tube being filled with a hydraulic fluid or the like and having an expandable portion which is adapted to be expanded when the tube is flexed.
 6. A signalling device as in claim 5, wherein a microswitch is mounted in said sensing means adjacent said expandable portion of said tube and is adapted to be operated by said tube when the tube expands upon being flexed, said microswitch being operatively connected to said source of electrical energy for establishing and interrupting an electrical circuit between said source of energy and said signalling means.
 7. A signalling device as in claim 6, wherein said signalling means comprises a speaker for emitting an audible signal.
 8. A signalling device as in claim 6, wherein said signalling means includes a vibrator adapted to be positioned adjacent the body of the skier for indicating to the skier through the sense of touch that the skier or the like is not in the proper position.
 9. A signalling device as in claim 6, wherein the signalling means comprises means for causing a mild electrical shock to be transmitted to the skier when he is not in the proper position.
 10. A signalling device as in claim 6, wherein said signalling means comprises a speaker for emitting an audible signal, a vibrator for signalling the skier through the sense of touch, and a light for giving a visual signal when the skier is not in the proper position.
 11. A signalling device as in claim 10, wherein said source of electrical energy and said speaker are mounted in an audio and power unit, and wherein a control knob is provided on said power unit for increasing or decreasing the volume of sound by the speaker.
 12. A signalling device as in claim 11, wherein said control knob is operatively connected to said source of electrical energy for selectively energizing and deenergizing said signalling device.
 13. A signalling device as in claim 12, wherein said control knob includes means for selectively energizing either said speaker or said vibrator.
 14. A signalling device as in claim 13, wherein a switch means is provided on said audio and power unit operatively connected to said source of energy for simultaneously energizing said speaker and said vibrator.
 15. A signalling device as in claim 14, wherein said microswitch is adjustably positioned relative to said expandable tube whereby the amount of expansion of said tube necessary to actuate said microswitch may be varied to accommodate persons of different size or different stance.
 16. A signalling device as in claim 15, wherein said sensing means and said signalling means are connected to said source of energy by means of flexible leads or wires.
 17. A signalling device as in claim 16, wherein said flexible leads are connected to said sensing means through a bayonet-type connection.
 18. A signalling device as in claim 17, wherein said flexible member comprises a generally tongue-shaped member adapted to be worn between the upper front surface of the skier''s foot and the boot whereby when the skier''s knees are flexed or bent properly for skiing, the flexible member is distorted and the flexible tube is at least partially collapsed to cause the hydraulic fluid therein to expand the expandable portion of the tube to open the microswitch.
 19. A signalling device as in claim 17, wherein said flexible member comprises an anklet adapted to be worn about and encircle the ankle of the skier whereby wHen the skier''s knees are flexed or bent properly for skiing the flexible member is distorted and the flexible tube is at least partially collapsed to cause the hydraulic fluid therein to expand the expandable portion of the tube to open the microswitch.
 20. A signalling device as in claim 19, wherein said flexible tube is positioned in the front central portion of said anklet.
 21. A signalling device as in claim 1, wherein said sensing means is positioned at the knee of the skier.
 22. A signalling device as in claim 21, wherein said sensing means includes switch means operable in response to the position or degree of flexure of the skier''s knee.
 23. A signalling device as in claim 22, wherein said sensing means is carried by upper and lower leg strap means adapted to be adjustably positioned about the leg of the skier above and below the knee, respectively.
 24. A signalling device as in claim 23, wherein said switch means comprises a microswitch carried by one of said leg strap means and microswitch-actuating means carried by the other of said leg strap means.
 25. A signalling device as in claim 24, wherein said microswitch-actuating means includes a shaft adjustably positioned in a bracket.
 26. A signalling device as in claim 25, wherein said microswitch and said shaft are carried on respective bracket means fixed to a respective leg strap means.
 27. A signalling device as in claim 26, wherein said bracket means fixed to said leg strap means are pivotally interconnected to one another.
 28. A signalling device as in claim 27, wherein said microswitch and said shaft are positioned at the side of the knee.
 29. A signalling device as in claim 28, wherein said signalling means comprises a speaker for emitting an audible signal.
 30. A signalling device as in claim 28, wherein said signalling means includes a vibrator adapted to be positioned adjacent the body of the skier for indicating to the skier through the sense of touch that the skier is not in the proper position.
 31. A signalling device as in claim 28, wherein the signalling means comprises means for causing a mild electrical shock to be transmitted to the skier when he is not in the proper position.
 32. A signalling device as in claim 28, wherein said signalling means comprises a speaker for emitting an audible signal, a vibrator for signalling the skier through the sense of touch, and a light for giving a visual signal when the skier is not in the proper position. 